Model Output Discussion - Staying cold into the new year

[ICE COLD]

See you next year polar vortex

[TSNWK]

4 minutes ago, Stu_London said:

Still no nailed on widespread snow event 

Suspect some will fall next week and there will be accumulations in places but uppers and dewpoints remain the main issue. 

On that point.  I checked for eastern kink.. around 96.  Hard to tell, but on the 850s the green stopped about 100 miles further south in Poland little steps and if we can squeeze another bit in the morning runs we might just tip the balance for next week.  Certainly too be continued....

[Tim Bland]

9 minutes ago, Griff said:

GFSP is great for Greenland, shame we aren't getting the goodies... 

Now I understand west based concerns, very well demonstrated on 18z.

 

 

Looks ok to me away from the beaches of Cornwall? I’m quite shallow...all I want is snow

Edited December 30, 2020 by Tim Bland

[kold weather]

7 minutes ago, ALL ABOARD said:

Of course. 

But that's usually down to the strength of the sun which causes additional energy. 

Null and void this time of year. 

Doesn't need to be strong LP. just needs to be elongated in a way that would eventually promote a SW type airflow.

Thats what way the Para GFS goes deeper in FI as the upper blocking morphs into a very west based -ve NAO type pattern, so much so its almost not a -ve NAO anymore as a weak lobe of the PV slips into its wake.

Thats a far from unlikely pattern and one that the ensembles have been constantly flagging up for some time. Very long way away still of course, just showing a possiblity!

Edited December 30, 2020 by kold weather

[Gowon]

2 minutes ago, ICE COLD said:

See you next year polar vortex

We don't want him to ever come back!

[IanT]

So where is the “POMIC” (point of maximum interest in charts) now? 6th Jan..?

 

[ALL ABOARD]

See that purple blob with black in the middle? 

Coming this way on the 18z..  

All academic but fun to look at all the same....

 

[Mucka]

Great pub run, pretty much the best case snowy scenario I described earlier when the troughs phase.

The only reason it isn't a COBRA run in FI is because each time we were about draw in -10/-12 uppers the flow switched from N to E or E to N stopping the flow and introducing more warm sectors.

If the synoptic comes off and either or both the Northerly and Easterly components are sustained another 48 hours then it will satisfy even the Inuk's among our number.

Edited December 30, 2020 by Mucka

[Griff]

5 minutes ago, Tim Bland said:

Looks ok to me away from the beaches of Cornwall? I’m quite shallow...all I want is snow

Yes, and no, if GFS solution is preferred

Any support in the anomaly charts etc for this, I thought Greenland high and block to lock off the Atlantic but keep things over us. 

GFSP timely reminder of potential calamity in FI. 

Edited December 30, 2020 by Griff

[feb1991blizzard]

15 minutes ago, northwestsnow said:

God I hope its right Steve 

BOOM!

Edited December 30, 2020 by feb1991blizzard

[Kasim Awan]

Growing GEFS support for the next Northerly. 12Z vs 18Z mean.

[Nick F]

The trend is there from this evening's GFS and EC operationals backed up by the ensembles, for the easterly next week to be superseded by a northerly as low heights / lobe of the trop PV gets flushed out from the arctic towards northern Europe later next week. Perhaps a response from the top down of the Strat warming over the pole.

The concern is the lobe of low heights / trop PV dropping south does so too far west, due to the Altantic block retrograding too far. But 18z GFS doesn't do this and better still, after a brief northerly, the lobe of low heights dropping south gets absorbed by the upper low over southern Europe with a ridge bridge between Atlantic and Russian highs, with a colder easterly than the one next week. But that's way off in the future and unlikely to pan out like that.

But the northerly after the easterly next week looking more and more likely for now.

Edited December 30, 2020 by Nick F

[Allseasons-Si]

The mean is a lot better with the heights in the Atlantic than the 12z

18z 192 v's 12z 204

 

[kold weather]

The ensembles show that the 18z probably is up there as one of the most progressive runs in bringing the deep cold over our shores. Therefore its very much a best case sceanario.

The other things gleaming thorugh the ensembles out to 180hrs, there is a really wide range of solutions out there, even at 144hrs. The mean is going to be next to useless as many are showing very different patterns.

For example, some show high pressure leaning into the UK, others have HP into Greenland, others have a mid Atlantic high with LP's riding over the top. All will show the central high pressure in the Atlantic like Kasim's chart, but all have VERY different prospects for future cold.

The easterly also looks at least a little cooler on some of the runs, not all of them but in the fine margins we are talking about it may bring more places into play next week.

Edited December 30, 2020 by kold weather

[Tim Bland]

3 minutes ago, Griff said:

Yes, and no, if GFS solution is preferred

Any support in the anomaly charts etc for this, I thought Greenland high and block to lock off the Atlantic but keep things over us. 

GFSP timely reminder of potential calamity in FI. 

Agree, GFS is much better, most years though we would give our left testicle for the gfs(p) shows how spoilt we are this year! 

[Kasim Awan]

Just now, kold weather said:

The ensembles show that the 18z probably is up there as one of the most progressive runs in bringing the deep cold over our shores. Therefore its very much a best case sceanario.

The other things gleaming thorugh the ensembles out to 180hrs, there is a really wide range of solutions out there, even at 144hrs. 

The easterly also looks at least a little cooler on some of the runs, not all of them but in the fine margins we are talking about it may bring more places into play next week.

Not sure it's a best case scenario - the outcome of a northerly push is being favoured quite considerably now for a few reasons.

[DavidS]

Yes it’s FI, but look where the vortex is.

[Allseasons-Si]

1 minute ago, kold weather said:

The ensembles show that the 18z probably is up there as one of the most progressive runs in bringing the deep cold over our shores. Therefore its very much a best case sceanario.

The other things gleaming thorugh the ensembles out to 180hrs, there is a really wide range of solutions out there, even at 144hrs. 

The easterly also looks at least a little cooler on some of the runs, not all of them but in the fine margins we are talking about it may bring more places into play next week.

It's in line with the rest of the ens though KW

[kold weather]

1 minute ago, Kasim Awan said:

Not sure it's a best case scenario - the outcome of a northerly push is being favoured quite considerably now for a few reasons.

Hi mate, Ive just looked through all the ensembles run by run, the 18z GFS op is probably in the top 3 in terms of the speed and cleaness of getting the cold down.

Many do evolve cold of course, but the 18z GFS is in the top league for evolutions from what I've seen

[Allseasons-Si]

I thought that i would give 18z a rerun in motion,...MORE PLEASE TOMORROW

at least Europe will cool down,that's a positive going into Jan.

[Kasim Awan]

Just now, kold weather said:

Hi mate, Ive just looked through all the ensembles run by run, the 18z GFS op is probably in the top 3 in terms of the speed and cleaness of getting the cold down.

Many do evolve cold of course, but the 18z GFS is in the top league for evolutions from what I've seen

I agree in terms of the microdetails it's probably in the top 15% as you say. The evolution is not untoward from a logical perspectice as it has been expected for some time now, and it is synoptically viablw. The depth of cold / snow on the 18z op is probably somewhat on the better side of possible solutions. This depends on how far east the diving low is. A further few days needed to gain some confidence on these details.

This has been a recurring pattern top, northerly shots.

[sukayuonsensnow]

Just for fun post:

Would be great if that purple area of cold moved ever closer to the UK. A few runs have shown this at the end recently.

In reality, next week still looks uncertain on the detail at this stage. I suspect cold with outbreaks of mostly rain from the east (maybe wintry on higher ground). The temperatures are just a touch too mild. What happens with that high pressure is very much TBD especially later next week.

[Allseasons-Si]

The control run is going for it.

[kold weather]

2 minutes ago, Allseasons-si said:

It's in line with the rest of the ens though KW

take a look at the synoptics of each run between 168-192hrs, you'll see what I mean!

For example this:

Is as cold as this:

Both have 850hpa temperture around -6/7c so show the same on the ensemble chart above...(as it happens I think that chart with the mid atlantic high will go cold anyway!)

So whilst I get that its within the mean, its also fair to say the mean hides alot of synoptic noise in there at this point. 

In a better note, there are some seriously good ensemble members by 240hrs, so many do go cold, just not many are as quick or as good as the GFS 18z op, thats all.

[Mike Poole]

GFS pub run T384:

As they used to say on Scooby Doo, ‘YIKES”!   

We are being chased by a monster vortex beast, it’ll get us but we’ll rip the mask off and it will be @Steve Murr all the time .  Crazy run.  

Edited December 30, 2020 by Mike Poole